Replacement diff lock actuator

[beermonster]

I got this from one of the American forums

You can use Mercedes part number 000-800-69-75 or 123-800-33-75 to replace Audi part number 857 711 995A or 997. You have to thread the output shaft using a 4mm x 0.7mm die, and re-use the yoke from the old unit. Clamp the shaft before cutting the thread to avoid damage top the diaphragm. Otherwise plug and play.....

I haven't confirmed this myself, as I've no need to at the moment. So this is just an FYI, I can't guarantee that it's right......

The incentive is that the mercedes unit is £17.52+VAT...... Audi is in the £60 territory

[Tim2004]

That's a good find. I've been meaning to sort out the ones on my 80q for some time, though it's difficult to test that it is the actuator or a hose/whatever problem, I'm not keen on getting under a running car even if it is on axle stands. Another excuse to buy a 4-post ramp...

[quattroman4x4]

Eventually got around to removing Center Diff lock Actuator- Bstrd of a job when lying on your back with the front up on standard car ramps.Right arm scratched to bits from entering the hole in the wheel arch.
Any way couldnt repair as planed due to breaking thread off on end of actuator that goes into part 857-711-479.
Any way both actuator 857-711-995 A and connecting piece 857-711-479 are back order only and expected to be NLA
Audi Price for Actuator is £67.43 +VAT
Nearly equivalent Mercedes Part Number is still Only £17.85+ VAT and available within one day from order.
Bear in mind the Merc W123 Part is of same era as quattro but parts are still available.